Needle vibration controlling mechanisms for zigzag sewing machines



A. F'LDAMICO 2,858,782 NEEDLE VIBRATION CONTROLLING MECHANISMS FOR Nov.4, 1958 ZIGZAG SEWING MACHINES 2 Sheets-Sheet 1 Filed May 26, 1954INVENTOR. Anthony E Ohm c0 WITNESS I 777 ATTORNEY A. F. DAMICO 2,858,782NEEDLE VIBRATION CONTROLLING MECHANISMS FOR w Nov. 4, 1958 ZIGZAG SEWINGMACHINES 2 Sheets-Sheet 2 Filed May 26, 1954 INVENTOR.

Anthony I? Dldm/co ATTORNEY NEEDLE VIBRATION CONTROLLING MECHA- NISMSFOR ZIGZAG SEWING MACHINES Anthony F. DAmico, South Norwalk, Conn.,assignor I to The Singer Manufacturing Company, Elizabeth,

N. 3., a corporation of New Jersey Application May 26, 1954, SerialN0.4s2,423

4 Claims. 7 (11. 112-158) This invention relates to improvements inzigzag stitch sewing machines of a laterally vibrating needle type andhasfor an object to provide such a machine with-a novel mechanismincluding a rotary pattern cam for producing the lateral needlevibrations.

Another object of the invention is to provide means whereby the needlemay be properly positioned laterally of the normal direction of workfeed independently of the rotary pattern cam so as to produce straightstitching in a predetermined path.

A further object of the invention is to provide means whereby the needlemay be maintained in a predetermined operable position whenever therotary pattern cam is removed from the machine.

With the above and other objects in view, the invention comprises thedevices, combinations, and arrangements of parts hereinafter describedin connection with the accompanying drawings which illustrate apreferred embodiment of the invention, from which the several featuresof the invention and the advantages attained thereby will be readilyunderstood by those skilled in the art.

In the drawings:

. Fig. 1 represents a rear side elevation view of a sewing machinecontaining the presentimprovements and having its top and rear coverplates removed whereby the internal mechanism may be viewed.

Fig. 2 represents, on an enlarged scale, a-sectional view takensubstantially along the line 2-2 of Fig. 1.

Fig. 3 represents, on an enlarged scale, a sectional view takensubstantially along the line 3-3 of Fig. 1.

Fig. 4 represents, on anenlarged scale, ai-sectional view takensubstantially along the line 4-4 of Fig. 1.

Fig. 5 represents a sectional View taken substantially along the line5-5 of Fig. 4.

Fig. 6 is a fragmentary view of the front side of the sewing machine andparticularly illustrating the pattern cam, the cam follower and a manualcontrol means for altering the movements of the needle-bar as impartedthereto by the rotary cam.

Fig. 7 represents, on an enlarged scale, a sectional view takensubstantially along the line 7-7 of Fig. 6.

. Referring-to the drawings, the sewing machine illustrated has abed-plate 10 afiording a'work-support-from one end of which bed-platerises a hollow standard 11 ofv a bracket-arm 12 overhanging thebed-plate and terminating at its-free end in a head .13; 3 Thebracket-arm 12 is open at its upperportion as at 14 (see Fig. 2) and atits back side as at 15 (see Fig. 1), which openings are adapted to beclosed by means of cover-plates, not herein shown, which may beremovably secured in positions over the openings 14 and 15 by anyconventional means. I 1

. R-otatably journaledin suitable bearings provided in the .bracketrarml12 is a horizontally disposed main shaft 16 extending. lengthwiseof thebracket-arm andcarrying at itsone end a. driving pulley 17., -At itsopposite end, the main shaft 16 is connected to drive a conventional"ice 2 type of needle thread take-up mechanism, not herein shown, aswell as a needle-bar designated by the numeral 18.

The needle-bar 18 carries at its lower end a needle 19 and is journaledfor endwise reciprocation in suitable bearings provided in a vibratoryframe or gate 20. The frame 20 is pivotally hung in a conventionalmanner upon a screw stud 21 carried by the upper portion of the head 13to provide for swinging movements of the frame 20 about a pivot axissubstantially transverse to the axis of rotation of the main shaft 16.For more detailed.

views and explanations of the present type of vibratory needle-barframe, reference may be had to U. S. Patent No. 2,297,197, of Bolter,dated September 29, 1942.

Cooperating with the needle 19 below the bed-plate 10 in'the formationof stitches is the usual loop-taker mechanism which is not hereinillustrated and forms no part of the present invention. Also locatedbeneath the bed-plate 10 but not herein illustratedv is the usual typeof work-feeding mechanism.

Extending rearwardly from the lower end of the needle-bar frame 20 is anarm 22 to which a pitman 23 is pivotally secured by means of a pivotstud 24. The pitman 23 is disposed within and lengthwise of the hollowbracket-arm 12 so that its rear end portion may be connected withmechanism which actuates the pitman back and forth lengthwise of itselfthereby to impart lateral Zigzag movements to the needle-bar frame 20and its associated needle 19. This mechanism may also be adjusted so asto position the needle-bar frame in a fixed position thereby to permitthe needle 19 to be reciprocated up and down in a fixed vertical path toproduce straight stitching.

More specifically, the rear end of the pitman 23 is provided with aterminal portion 25 which is adapted to be connected by Way ofmechanism, hereinafter described in detail, to a rotary pattern cam 26,of which the peripheral portion 27 may be tracked by a cam follower forthe purpose of imparting a predetermined pattern of motion to the pitman23 to the end that a predetermined pattern of ornamental stitching maybe produced by the sewing machine.

The rotary pattern cam 26, as will hereinafter be described, may beremoved from the machine to theend that other pattern cams may besubstituted therefor so that the operator may produce various types ofornamental stitch patterns by merely changing the pattern cams. Also, aswill hereinafter be described, the pattern,

cam 26 may be entirely removed from the machine and means are providedwith the machine whereby it may be operated in a mannerof a conventionalstraight stitching machine.

Referring particularly to Figs. 1 and 2, the pattern cam 26 is providedwith a central aperture 28 so that the cam may be mounted upon thedistalgend portion of a shaft 29 which is suitably mounted in bearingbosses 30 and 31 formed within the bracket-arm 12. The distal endportion of the shaft 29 is provided with a cylindrical collar 32 againstwhich the cam 26 may be placed and locked by means of a thumb nut 33.The thumb nut 33 may be tightened against the cam '26 due tothe factthat the outboard end of the shaft 29 is threaded. So as to time the cam26 with the remaining portion of the sewing mechanism, the shaft hub32-is provided with a pin 34 which is adaptedto engage an appropriateaperture 35 formed within the cam 26. .An intermediate portion of therotary cam shaft 29 has fixed.

thereon a gear 36 which meshes with a worm gear 37 fixed upon the rotarymain shaft 16. Thus, rotation of the main shaft 16 will, through thegears 36 and 37, rotate the cam 26 at a predetermined speed.

Referring particularly to Figs. 1, 2 and 6, there is mounted'withinandbetween the side walls of the bracket-arm 12 an oscillatory shaft 38which is disposed in parallelism with the rotary cam shaft 29. Theopposite end portions of the rock-shaft 38 extend through theirassociated side walls of the sewing machine bracketarm 12 and theforward end of the shaft 38 has fixed thereon, in a conventional manner,a bell-crank lever 39 (see Fig. 6) of which one arm 40 carries alaterally projecting follower element 41 which is normally biased intoengagement against the periphery 27 of the cam 26 by means of a coilspring 42.

As may be best seen from Figs. 1 and 2, the spring 42 has its one endportion secured to a post 43 fixed Within the bearing boss 30, while theother end portion of the spring is connected with a post 44 carried by-acollar 45 fixed to the rock-shaft 38 in a conventional manner. Thespring 42 will urge the rock-shaft 38 to turn in a direction" such thatthe cam follower 41 Will faithfully track the peripheral portion of thecam 26 to'the vendjthat the rock-shaft 38 will be oscillated back andforth in conformity with the pattern of the cam.

As may be observed from Fig.6, an arm 46 of the bell-crank lever 39 isdisposed directly beneath a boss 47 provided on the forward side of thebracket-arm 12, which boss is disposed directly within the path ofmovement of the arm 46 which has threaded therein a screw 48 which mayengage the boss 47 so as to function as an adjustable stop for arrestingthe downward movement of the arm 40 in the event that the cam 26 isremoved from the machine. A nut 49 cooperates with the screw 48 so as tolock the latter in any desired position of adjustment. Also, as willhereinafter be set forth in more detail, the screw 48 may be employedfor shifting the follower 41'out' of'engagement with the cam 26 whilethe latter is in its operative p osition.

The rear end portion of the rock-shaft 38 is provided with a radialcrank 50 fixed'to-th'e shaft 38 by means of a set screw 51. The endportion of the crank 50 is pivotally connected with a link 52 by meansof a conventional type of pivot screw 53. As may be seen from Figs. 1,2,3 and 4, the lower end portion of the link 52 is pivotally connectedwith the terminal portion 25 of the pitman 23 by means of a connectorpin 54. From the above, it will be understood that the rotation of themain shaft 16 will actuate the rotary pattern cam 26 through'the mediumof the gears 36 and 37 to the end that the rock-shaft 38 will beoscillated back and forth through the medium of its cam follower 41. Therocking of the/ shaft 38 will, in turn, oscillate its crank 50 and,thus, through the link 52, impart rising and falling motions to theterminal portion 25 of the pitman 23. In order to translate the lateralvibratory movements of the pitman 23 into effective endwisereciprocatory movements, thereby to impart'swingin'g movements to theneedle-bar frame 20, a guide block 55 is carried upon the inner endportion of the pin 54, which guide block is shiftably disposed within aguideway 56 constituted by a rearwardly open slot formed in the outer orrearwardly exposed face of a bodily adjustable guide member 57. Theguide member 57 is rigidly locked by means of a shoulder screw 58 to acrank member 59 which is integrally formed upon the rear end portion ofa'" hollow shaft 60 which is rockably supported within an aperture 61formed within the bracket-arm 12.

More specifically, the guideway 56 is cylindrical in form and hasslidingly received therein the guide member 55 which is also cylindricalin form and which is secured to the inner end portion of the pivot stud54 by means of a screw member 62. From this, it will be apprecitaed thatthe rotary movements of the cam shaft 29'wi1l, through the link 52,actuate the guide 55 length- Wise of the guideway 56 so as to produceendwise movements in the pitman 23 in accordance with the angularadjustment of the guide member 57. Manifestly, whenever the guide member57, together with its associated member 59, are disposed-in a mannersuch that their common longitudinal axis forms a ninety degree anglewith the line connecting the centers of the pivot pins 24 and 54 of thepitman no substantial endwise movement will be imparted to theneedle-bar gate 20 and, thus, the needle 1? will be permitted toreciprocate up and down in a fixed vertical path. However, by the sametoken, when the guide member 57 with its associated member 59 areadjusted about the longitudinal axis of their shaft 60, the needle-barframe 20 will be moved back and forth lengthwise of the bed-plate 10 soas to produce zigzag stitches. From this, it will be appreciated that asthe angle between the longitudinal axis of the guideway 56 becomes moreacute relative to the line connecting the pitman pivot axes 24 and 25the greater will be the amplitude of lateral movement imparted to theneedle-bar frame 20.

From the above, it will be readily appreciated that with the operationof the present machine a rotary pattern cam 26 having a predeterminedperipheral shape may be placed upon the machine in a manner ashereinabove described for producing a predetermined pattern of movementof the needle-bar frame 20. However, it will also be understood that asthe guide member 57 is angularly adjusted about its pivot axis thepattern of movement imparted to the needle-bar frame 20 by the rotarypattern cam may be altered so as to increase or decrease the amplitudeof lateral needle-bar vibration.

In order to facilitate the adjustment of the guide member 57, the hollowshaft 60 extends beyond the confines of the bracket-arm 12 and hasmounted thereon a hand lever 63. As may be best seen from Figs. 2, 6 and7, the hand lever 63 is provided with a finger piece 64 whichfacilitates the manual adjustment of the member 63. Also provided on themember 63 is a pointer element 65 which traverses across the face of thebracket-arm 12. For the purpose of indicating the amount of adjustmentthe bracket-arm may be provided with appropriate indicia numbers whichare generally indicated by the'numeral 66. In order to lock the handmember 63 many position of adjustment, there is associated therewith ahand screw 67 which is threaded directly into the bracket-arm 12 andwhose shank is disposed within an arcuate'slot 68 formed within the handlever 63. By. tightening a thumb nut 67"against the lever 63, the lattermay be locked in any selective position of adjustment.

As hereinabove pointed out, the bell-crank lever 39 with its cam"follower 41 is provided with an abutment arm 46 which, together with theboss member 47, function to arrest the downward movement ofthe'foll'ower arm 40 under the action of the coil spring 42 whenever thecam member 26 is removed from the machine. From this, it will beunderstood that with a proper adjustment of the screw 48 carried by thebell-crank lever 39, the arm 40 may be arrested in its downward movementin a position such that the needle-bar gate 20 may be maintained in anoptimum position for producing straight line stitching upon the removalof the pattern cam 26. However,

as also hereinabove pointed out, straight stitching may be effected evenwith the rotary'pattern cam in place whenever the guide member 57 isadjusted so that its longitudinal axis will form a ninety degree anglewith a line connecting the pitman pivot studs 24 and 54. However, sincethe axis of the guideway 56 is straight rather than curved, some smalldegree of endwise movement will beimparted to the needle 19 by the cam26 even though the guideway is placed in its so-called no-movementposition. Therefore, under some circumstances, the operator might desireto remove the cam 26 whenever straightaway stitching is to be effectedby the machine.

The present invention also contemplates a second form of'adjusting meanswhich will enable the operator mannally to position the needle-bar frame20 upon the removal of the cam 26. Referring particularly to Figs. 3 to7, there is rockably disposed'within the hollow shaft 60 a shaft 70whose inner end carries eccentrically thereof a pin 71 which is disposedwithin a slot 72 formed within a plate 73 slidably mounted within arectangular opening 74 formed between the ,elements'57 and59 of theguide member structure. The lower portion vof the. plate 73 carries apin 75 which projects into the guideway 56. However, whenever the shaft70 is adjusted so that its eccentric pin 71 is in its lowermostposition, the pin 75 of the plate 73 is disposed below the guide 55 soas not to engage the guide during its normal cam-actuated endwisemovements within the guideway 56. However, by shifting the shaft 70about its longitudinal axis the pin 75 may be made to engage the lowerportion of the guide element 55 thereby to elevate the latter elementlengthwise of the guideway 56. From this, it will be appreciated thatwith this mechanism it is possible to raise the cam follower 41 to aposition where it will no longer engage the cam 26 and this action willeffectively arrest all lateral movements of the needle-bar frame 20 andits associated needle 19.

However, this adjusting mechanism is primarily adapted to be employedwhenever the cam 26 is removed from the sewing machine. It iscontemplated that upon the removal of the cam 26 the shaft 70 may beadjusted so as to place the needle 19 in any one of several selectivepositions of adjustment laterally of the Work-support 10, thereby toposition the needle in its optimum position for straightaway stitching.In order to facilitate this adjustment of the shaft 60, its forward endportion carries a hand lever 76 fixed upon the reduced end portion 77 ofthe shaft 70 by means of a set screw 78. Referring particularly to Figs.6 and 7, it will be appreciated that upon the turning of the hand lever76 the pin 75 will be raised and lowered so as to shift the guide 55 upand down within the guideway 56 all of course under the influence of thecoil spring 42. The hand lever 76 is placed in sliding arrangement withthe first mentioned hand lever 63, and as may be best observed in Figs.6 and 7, the face of the lever 63 is provided with three small aperturesdesignated by the numerals 79, 80 and 81, which apertures or detentscooperate with a plunger 82 for the purpose of producing a tactualsignal which indicates to the operator any one of three predeterminedpositions of the needle 19. More specifically, the plunger 82 is mountedwithin an aperture 83 formed within the hub portion of the hand lever76, which aperture 83 has its one end adapted to be closed by a screw 84which forms an abutment seat for a spring 85 which biases the plunger 81towards the face of the hand lever 63. From this, it will be appreciatedthat as the operator turns the handle 76 relative to the hand lever 63the plunger will be shifted over the face of the hand lever 63 and willfind its way into any one of the three detent apertures 79, 80 or 81thereby to advise the operator that the needle is positioned in itsextreme left-hand, middle or right-hand positions relative to the lengthof the bed-plate. Therefore, the operator may place the needle in any ofthese positions and thereafter produce straightaway stitching wheneverthe cam 26 is removed from the machine. Naturally, all upward movementsof the guide element 55 lengthwise of the guideway 56 are made inopposition to the spring 42 and, therefore, as the hand lever 76 ismoved back and forth the guide element 55 will faithfully shift up anddown lengthwise of the guide member 56 in response to the movements ofthe handle 76 and the action of the spring 42.

Having thus set forth the nature of the invention, what I claim hereinis:

1. In an ornamental seam sewing machine having a hollow bracket-arm, avibratory needle-bar frame carried by said bracket-arm, a needle-barjournaled for end- Wise reciprocation in said frame, a rotary patterncam 7 removably mounted upon said machine, a c'am'follower element forengaging said cam, a pitrn'an connecting said follower element with saidframe for imparting the mo-- tions of said pattern cam to said frame, ahollow shaft mounted within said bracket-arm for rocking movements aboutits longitudinal axis, a guideway fixed upon said hollow shaft foraltering the, needle-frame vibrating movement produced by said patterncam in response to movements of said hollow shaft, guide means carriedby said pitman and traversing said guideway during the operation of saidpattern cam, and manually operable means including a rotative shaftmounted within and lengthwise of said hollow. shaft for shifting saidguide means relative to said guideway whenever the pattern cam isremoved from the machine thereby to vary the position of said needle-barframe.

2. In an ornamental seam sewing machine having a hollow bracket-arm, avibratory needle-bar frame carried by said bracket-arm, a needle-barjournaled for endwise reciprocation in said frame, a rotary pattern camjournaled upon said machine, a cam follower for engaging said cam,spring means to bias said follower toward said cam, a hollow shaftmounted within said bracket-arm for rocking movements about itslongitudinal axis, manually operable means for rocking said shaft aboutits axis, a guideway fixed at one end upon said hollow shaft, a pitmanhaving a first end thereof connected with said frame for vibrating thelatter ele, ment, guide means carried by a second end of said pitman anddisposed within said guideway so as to be shifted lengthwise thereof,means connecting the second end of said pitman with said cam follower soas to shift said guide means lengthwise of said guideway, and manuallyoperable means including a rotative shaft mounted within and lengthwiseof said hollow shaft and an element disposed eccentrically of suchrotative shaft and engageable with said guide means thereby to shiftsuch guide means lengthwise of said guideway and against the action ofsaid spring means.

3. In an ornamental seam sewing machine having a hollow bracket-arm, avibratory needle-bar frame car-' ried by said bracket-arm, a needle-barjournaled for endwise reciprocation in said frame, a rotary pattern camjournaled upon said machine, a cam follower for engaging said cam,spring means biasing said follower toward said cam, connections betweensaid'follower and said frame for imparting the motions of said patterncam to said frame, a shaft journaled about its longitudinal axis andwithin said bracket-arm, with one end of .said shaft being connectedwith said cam follower and the other end being exposed at the front sideof said bracket-arm, a handle connected with the exposed end of saidshaft whereby said shaft may be turned thereby to shift said camfollower away from said cam and against the action of said spring, andmeans for releasably locking said handle in any one of a plurality ofselective positions of adjustment.

4. In an ornamental seam sewing machine having a hollow bracket-arm, avibratory needle-bar frame carried by said bracket-arm, a needle-barjournaled for endwise receiprocation in said frame, a rotary pattern camjournaled upon said machine, a cam follower for engaging said cam,spring means biasing said follower toward said cam, connections betweensaid follower and said frame for imparting the motions of said patterncam to said frame, said connections including an elongated guideway witha guide element slidingly mounted therein, a shaft journaled about itslongitudinal axis and within said bracket-arm with one end of said shaftbeing connected with said cam follower through said guide element andthe other end being exposed at the front side of said bracket-arm, 'ahandle connected with the exposed end of said shaft whereby said shaftmay be turned thereby to shift said cam follower away from 7 said camandagainst the action of-said spring, and means 2,297,197 for;releesab1ylocking saidhandle in any one of a plu- 2,669,204 rality of; selectivetpositionsyof adjustment.

References Citedi n the file of this patent 5- UNITED;SIENIES PATENTS7,213 9643641 1,551;4 S3 Arbn'son et a1. Aug. 25, 1925 8 Bolter-. Sept;29, 1942;: Urscheleri t Feb.V16,. 1954" FOREIGNPATENTS Great Britain of1908 Great Britain of 1909 France: Feb. 8, 1950

